Turns are parsed incorrectly from streaming chunks in `chat_snowflake()`

[atheriel]

Follow-up from #533: turns are still parsed incorrectly when streaming with chat_snowflake():

> chat <- chat_snowflake(model = "claude-3-7-sonnet")
> chat$chat("Briefly list your favourite SQL dialects.")
# My Favorite SQL Dialects

1. PostgreSQL - Robust, ACID-compliant, with excellent JSON support and advanced features
2. SQLite - Lightweight, serverless, perfect for embedded applications
3. MySQL/MariaDB - Popular, good performance, widely supported
4. Microsoft SQL Server - Strong enterprise features and integration with Microsoft ecosystem
5. BigQuery SQL - Great for analytics on large datasets

Each has strengths for different use cases, from embedded applications to enterprise data warehousing.
> chat$last_turn()@text
[1] "#"

Peeking at chat$last_turn()@json seems to indicate that we might not be parsing the deltas correctly:

Full str() output

> > chat$last_turn()@json |> str()
List of 4
 $ id     : chr "bac82de4-daeb-4cf5-b335-04b417d7e30b"
 $ model  : chr "claude-3-7-sonnet"
 $ choices:List of 47
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "#"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "#"
  .. .. ..$ text        : chr "#"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " My"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " My"
  .. .. ..$ text        : chr " My"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " Favorite SQL"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " Favorite SQL"
  .. .. ..$ text        : chr " Favorite SQL"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " Dialects\n\n1"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " Dialects\n\n1"
  .. .. ..$ text        : chr " Dialects\n\n1"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr ". Postgre"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr ". Postgre"
  .. .. ..$ text        : chr ". Postgre"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "SQL -"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "SQL -"
  .. .. ..$ text        : chr "SQL -"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " Robust"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " Robust"
  .. .. ..$ text        : chr " Robust"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr ", ACID-compliant"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr ", ACID-compliant"
  .. .. ..$ text        : chr ", ACID-compliant"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr ", with"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr ", with"
  .. .. ..$ text        : chr ", with"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " excellent JSON"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " excellent JSON"
  .. .. ..$ text        : chr " excellent JSON"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " support an"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " support an"
  .. .. ..$ text        : chr " support an"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "d advanced features"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "d advanced features"
  .. .. ..$ text        : chr "d advanced features"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "\n2. SQL"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "\n2. SQL"
  .. .. ..$ text        : chr "\n2. SQL"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "ite - Lightweight"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "ite - Lightweight"
  .. .. ..$ text        : chr "ite - Lightweight"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr ", server"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr ", server"
  .. .. ..$ text        : chr ", server"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "less, perfect"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "less, perfect"
  .. .. ..$ text        : chr "less, perfect"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " for embedded applications"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " for embedded applications"
  .. .. ..$ text        : chr " for embedded applications"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "\n3. MySQL"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "\n3. MySQL"
  .. .. ..$ text        : chr "\n3. MySQL"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "/"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "/"
  .. .. ..$ text        : chr "/"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "MariaDB -"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "MariaDB -"
  .. .. ..$ text        : chr "MariaDB -"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " Popular"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " Popular"
  .. .. ..$ text        : chr " Popular"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr ", goo"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr ", goo"
  .. .. ..$ text        : chr ", goo"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "d performance"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "d performance"
  .. .. ..$ text        : chr "d performance"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr ", widely"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr ", widely"
  .. .. ..$ text        : chr ", widely"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " supporte"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " supporte"
  .. .. ..$ text        : chr " supporte"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "d\n4. Microsoft"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "d\n4. Microsoft"
  .. .. ..$ text        : chr "d\n4. Microsoft"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " SQL Server - Strong"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " SQL Server - Strong"
  .. .. ..$ text        : chr " SQL Server - Strong"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " enterprise"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " enterprise"
  .. .. ..$ text        : chr " enterprise"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " features"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " features"
  .. .. ..$ text        : chr " features"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " an"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " an"
  .. .. ..$ text        : chr " an"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "d integration"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "d integration"
  .. .. ..$ text        : chr "d integration"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " with Microsoft"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " with Microsoft"
  .. .. ..$ text        : chr " with Microsoft"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " ecosystem"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " ecosystem"
  .. .. ..$ text        : chr " ecosystem"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "\n5. Big"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "\n5. Big"
  .. .. ..$ text        : chr "\n5. Big"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "Query SQL"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "Query SQL"
  .. .. ..$ text        : chr "Query SQL"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " - Great"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " - Great"
  .. .. ..$ text        : chr " - Great"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " for analytics"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " for analytics"
  .. .. ..$ text        : chr " for analytics"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " on"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " on"
  .. .. ..$ text        : chr " on"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " large datasets"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " large datasets"
  .. .. ..$ text        : chr " large datasets"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "\n\nEach has streng"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "\n\nEach has streng"
  .. .. ..$ text        : chr "\n\nEach has streng"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "ths for"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "ths for"
  .. .. ..$ text        : chr "ths for"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " different use cases,"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " different use cases,"
  .. .. ..$ text        : chr " different use cases,"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " from embedde"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " from embedde"
  .. .. ..$ text        : chr " from embedde"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "d applications to enterprise"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "d applications to enterprise"
  .. .. ..$ text        : chr "d applications to enterprise"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr " data wareho"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr " data wareho"
  .. .. ..$ text        : chr " data wareho"
  ..$ :List of 1
  .. ..$ delta:List of 4
  .. .. ..$ type        : chr "text"
  .. .. ..$ content     : chr "using."
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr "using."
  .. .. ..$ text        : chr "using."
  ..$ :List of 1
  .. ..$ delta:List of 3
  .. .. ..$ type        : chr "text"
  .. .. ..$ content_list:List of 1
  .. .. .. ..$ :List of 2
  .. .. .. .. ..$ type: chr "text"
  .. .. .. .. ..$ text: chr ""
  .. .. ..$ text        : chr ""
 $ usage  :List of 3
  ..$ prompt_tokens    : int 16
  ..$ completion_tokens: int 113
  ..$ total_tokens     : int 129